JP5315875B2 - Image processing method and image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for image processing whereby erasure faults such as remains without erase are prevented even when high-speed erasure at an erasure speed of not lower than 150 mm/sec is carried out under a low-temperature environment where an environmental temperature in the periphery of a thermal reversible recording medium after image formation is lower than 15&deg;C. <P>SOLUTION: The method for image processing includes an image forming process for forming an image on the thermal reversible recording medium by heating the thermal reversible recording medium whose color tone changes reversibly depending on temperatures, a coloring concentration adjusting process for adjusting the coloring concentration of the image formed on the thermal reversible recording medium to be not lower than 88% to the maximum coloring concentration under the 20&deg;C environment of the image if the environmental temperature in the periphery of the thermal reversible recording medium after image formation is lower than 15&deg;C, and an image erasing process for erasing the image formed on the thermal reversible recording medium by heating the thermal reversible recording medium with the adjusted coloring concentration at the erasure speed of not lower than 150 mm/sec. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention does not cause erasure defects such as unerased even if high-speed erasure is performed at an erasing speed of 150 mm / sec or more in a low temperature environment where the ambient temperature of the thermoreversible recording medium after image formation is less than 15 ° C. The present invention relates to an image processing method and an image processing apparatus.

The erasing speed of rewritable printers currently on the market is about 20 mm / sec to 80 mm / sec.
Recently, in order to improve the erasing speed, a rewritable printer having a new heating device has been proposed (see Patent Documents 1 and 2). According to this proposal, the erasing speed of the rewritable printer is 150 mm / sec or more, and high-speed erasing that is about twice or more than the conventional speed can be realized.
However, if the thermoreversible recording medium printed out after erasure recording is left in a low-temperature environment where the ambient temperature is 15 ° C. or less and then erased at a high erasure speed of 150 mm / sec or more, erasure defects such as unerased residue will occur. At present, there is a problem of occurrence, and a quick solution is desired.

JP 2008-91321 A Japanese Patent No. 4086252

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, according to the present invention, erasure defects such as unerased are generated even when high-speed erasure is performed at an erasing speed of 150 mm / sec or more in a low temperature environment where the ambient temperature of the thermoreversible recording medium after image formation is less than 15 ° C. It is an object of the present invention to provide an image processing method and an image processing apparatus that do not have any.

  As a result of intensive studies by the present inventors to solve the above problems, the thermoreversible recording medium itself is kept at a normal temperature (20 ° C.) for a certain period of time while the thermoreversible recording medium is colored. Thus, it has been found that the color development of the image is stable, and the erasing speed is 150 mm / sec or more and can be erased at high speed.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> An image forming step of heating a thermoreversible recording medium whose color tone reversibly changes depending on temperature to form an image on the thermoreversible recording medium;
When the environmental temperature around the thermoreversible recording medium after image formation is less than 15 ° C., the color density of the image formed on the thermoreversible recording medium is set to the maximum color density of the image in a 20 ° C. environment. A color density adjustment step for adjusting to 88% or more;
An image erasing process comprising: heating an thermoreversible recording medium having an adjusted color density and erasing an image formed on the thermoreversible recording medium at an erasing speed of 150 mm / sec or more. It is.
<2> The image processing method according to <1>, wherein in the color density adjustment step, the image surface of the thermoreversible recording medium after image formation is heated to an environmental temperature of 15 ° C. to 20 ° C.
<3> The image processing method according to <2>, wherein the thermoreversible recording medium after image formation is heated while being conveyed to the printer tray.
<4> The image processing method according to <2>, wherein the thermoreversible recording medium after image formation is heated at an exit to the printer tray.
<5> The image processing method according to <2>, wherein the thermoreversible recording medium after image formation is heated in a printer tray.
<6> The thermoreversible recording medium has at least a thermoreversible recording layer on a support, the thermoreversible recording layer is in a first color state at a first specific temperature, and the first specific temperature The image processing method according to any one of <1> to <5>, wherein the second color state is obtained by cooling after heating at a second specific temperature higher than that.
<7> The image processing method according to <6>, wherein the thermoreversible recording layer contains at least an electron donating coloring compound and an electron accepting compound.
<8> Image forming means for heating a thermoreversible recording medium whose color tone reversibly changes depending on temperature to form an image on the thermoreversible recording medium;
When the environmental temperature around the thermoreversible recording medium after image formation is less than 15 ° C., the color density of the image formed on the thermoreversible recording medium is set to 88% of the maximum color density of the image in a 20 ° C. environment. Color density adjustment means for adjusting the color density to be at least%,
An image processing apparatus comprising: an image erasing unit that heats a thermoreversible recording medium having an adjusted color density and erases an image formed on the thermoreversible recording medium at an erasing speed of 150 mm / sec or more. It is.
<9> The image processing apparatus according to <8>, wherein the color density adjusting unit is a unit that heats the image surface of the thermoreversible recording medium after image formation to an ambient temperature of 15 ° C. to 20 ° C. .

  According to the present invention, conventional problems can be solved, and high-speed erasure with an erasing speed of 150 mm / sec or more is performed in a low-temperature environment where the ambient temperature of the thermoreversible recording medium after image formation is less than 15 ° C. However, it is possible to provide an image processing method and an image processing apparatus that do not cause erasure defects such as unerased residues.

(Image processing method and image processing apparatus)
The image processing method of the present invention includes an image forming process, a color density adjusting process, and an image erasing process, and further includes other processes such as a transport process and a control process as necessary.
The image processing apparatus of the present invention includes an image forming unit, a color density adjusting unit, and an image erasing unit, and further includes other units such as a conveying unit and a control unit as necessary.

The image processing method of the present invention can be suitably implemented by the image processing apparatus of the present invention, the image forming step can be performed by the image forming unit, and the color density adjusting step is performed by the color density adjusting unit. The image erasing step can be performed by the image erasing unit, and the other steps can be performed by the other unit.
In the image processing method of the present invention, the image is normally updated (the image erasing step) for the first time when the thermoreversible recording medium is reused, and then the image is recorded by the image recording step. The order of recording and erasing is not limited to this, and the image may be erased by the image erasing step after the image is recorded by the image recording step.

<Image forming step and image forming means>
The image forming step is a step of forming an image on the thermoreversible recording medium by heating the thermoreversible recording medium whose color tone reversibly changes depending on the temperature, and is performed by an image forming unit.
There is no restriction | limiting in particular as said image formation means, According to the objective, it can select suitably, For example, a thermal head, a laser, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
When a thermal head is used as the image forming means, the printing speed is preferably 5 mm / sec to 150 mm / sec, more preferably 10 mm / sec to 80 mm / sec. Further, the printing energy depends on the sensitivity characteristics of the thermoreversible recording medium and cannot be specified unconditionally, but is preferably 0.1 mJ / dot to 0.7 mJ / dot.

<Image erasing process and image erasing means>
The image erasing step is a step of heating a thermoreversible recording medium having an adjusted color density and erasing an image formed on the thermoreversible recording medium at an erasing speed of 150 mm / sec or more. Is called.

  There is no restriction | limiting in particular as said image erasing means, According to the objective, it can select suitably, For example, a laser beam, an infrared lamp, a heat roller, a hot stamp, a dryer etc. are mentioned.

The erasing speed is 150 mm / sec or more, preferably 150 mm / sec to 170 mm / sec.
Examples of the image processing apparatus provided with such an image erasing unit capable of high-speed erasing include a rewritable printer RP-K series manufactured by Shinko Electric Co., Ltd.

<Color density adjustment step and color density adjustment means>
The color density adjustment step was formed on the thermoreversible recording medium when the ambient temperature around the thermoreversible recording medium after image formation was less than 15 ° C. (specifically, −20 ° C. or more and less than 15 ° C.). This is a step of adjusting the color density of the image to 88% or more of the maximum color density of the image in a 20 ° C. environment, and is performed by the color density adjusting means. It is preferable to adjust the color density of the image formed on the thermoreversible recording medium to be 88% to 100% with respect to the maximum color density of the image in a 20 ° C. environment.
If the color density is less than 88%, the color density becomes thin and a half-colored color state is formed, so that the visibility is deteriorated and a sufficiently dark color state cannot be obtained. Moreover, it may become a state different from the target color. Furthermore, there is also a problem that the color erasing performance is inferior because a half-colored coloring state is generated and a phenomenon that sufficient erasing cannot be performed occurs.

When the ambient temperature around the thermoreversible recording medium after image formation is 15 ° C. or higher, the image surface of the thermoreversible recording medium after image formation is at an ambient temperature of 15 ° C. to 20 ° C. There is no need to perform an adjustment process. However, when an image is formed in a high-temperature and high-humidity environment (temperature of 30 ° C. or higher and humidity of 65% RH or higher), the image density may be lowered. It is preferable to stabilize the color development.
Here, the ambient temperature around the thermoreversible recording medium after the image formation means at least the ambient temperature where the thermoreversible recording medium after the image formation is left, and in a broad sense, after the image formation. It means the external environmental temperature in which the image processing apparatus in which the thermoreversible recording medium is placed or the environmental temperature inside the printer.

In the color density adjustment step, adjusting the color density of the image formed on the thermoreversible recording medium to be 88% or more with respect to the maximum color density of the image in a 20 ° C. environment is that after the image formation. This is synonymous with heating so that the image surface of the thermoreversible recording medium has an ambient temperature of 15 ° C to 20 ° C.
Here, heating the image surface of the thermoreversible recording medium after the image formation to an environmental temperature of 15 ° C. to 20 ° C. means that the image surface is heated after the image formation and the image is developed in a 20 ° C. environment. This means that the thermoreversible recording medium after image formation is held for at least 10 seconds to 5 minutes in a 20 ° C. environment. It may be held for 5 minutes or longer, and may be stored for a long time if the color image is stable.
Such a heating method is not particularly limited and may be appropriately selected depending on the purpose. For example, (1) a mode in which the thermoreversible recording medium after image formation is heated while being conveyed to the printer tray, (2 (2) A mode in which the thermoreversible recording medium after image formation is heated at the outlet to the printer tray, and (3) a mode in which the thermoreversible recording medium after image formation is heated in the printer tray. These may be used individually by 1 type and may use 2 or more types together.

In the aspect (1), for example, a heating method is provided in the conveyance path after image formation, and a heating method is used.
Examples of the heat treatment apparatus include a thermal head, a heating device, an erase bar, a heat roll, a hot stamp, a dryer, a heat bar, an infrared lamp, and a laser beam.
The heating conditions in the heat treatment apparatus are as follows: 30 ° C. for 5 seconds to 4 minutes, 40 ° C. for 2 seconds to 3 minutes, 50 ° C. for 1 second to 2 minutes, 60 ° C. for 0.5 seconds to 1 minute, 70 ° C. 0.2 seconds to 30 seconds at 80 ° C., 0.1 seconds to 15 seconds at 80 ° C., 0.05 seconds to 10 seconds at 80 ° C., 0.02 seconds to 5 seconds at 90 ° C., and the like. The heating time indicates the time for heating the entire medium. When the medium is transported on the transport path, it is the time for passing the medium through the transport path.

When the thermoreversible recording medium is heated at a temperature higher than 90 ° C., the surface of the medium is heated too much, so that the image at the time of color development is decooled. In other words, there is a phenomenon that the color density is lowered.
Moreover, if it is less than 30 degreeC, in order to raise the temperature of the medium surface, it must heat for a long time, Therefore It is inadequate as the temperature heated in a conveyance path.

Here, FIG. 1 is a diagram showing an example of the image processing apparatus of the present invention. The image processing apparatus shown in FIG. 1 includes a thermal head 52, a heating device 38, an RF-ID reader / writer 51, a transport roller 40, a heat processing apparatus 60, and a printer tray 50.
In this image processing apparatus, first, the image recorded on the thermoreversible recording layer is erased by heating with the heating device 38. Next, the RF-ID reader / writer 51 reads information on the RF tag in the thermoreversible recording medium, and the RF-ID reader / writer 51 records new information on the thermoreversible recording layer from the thermal head 52. .
The thermoreversible recording medium 5 is heat-treated for image erasure by the heating device 38, and the image is recorded by the thermal head 52. Thereafter, while the thermoreversible recording medium 5 is conveyed to the printer tray 50, the image processing surface 60 is heated by the heat treatment device 60, and the color density of the image formed on the thermoreversible recording medium is determined under the 20 ° C. environment of the image. Is adjusted to be 88% or more with respect to the maximum color density and is carried out into the printer tray 50. Note that the RF-ID may be rewritten before or after image erasing by the heating device.
Note that the heat treatment device 60 is controlled not to heat when the ambient temperature of the thermoreversible recording medium after image formation is 15 ° C. or higher, and to heat when the ambient temperature drops below 15 ° C. Yes.
In addition, the temperature of the heat treatment apparatus can be changed according to the ambient temperature, or the heating speed of the heat treatment apparatus can be changed to adjust the temperature so that the thermoreversible recording medium is heated and colored. Also good.

In the aspect (2), for example, a method of heating the thermoreversible recording medium by applying hot air at the exit of the printer tray can be used.
The heating conditions include 40 ° C. for 2 seconds to 3 minutes, 50 ° C. for 1 second to 2 minutes, 60 ° C. for 0.5 seconds to 1 minute, 70 ° C. for 0.2 seconds to 30 seconds, and 80 ° C. for 0 seconds. 1 second to 15 seconds, 0.05 second to 10 seconds at 80 ° C., and the like.

Here, FIG. 2 is a schematic diagram showing another example of the image processing apparatus of the present invention. The image processing apparatus of FIG. 2 has the same configuration except that a hot air blower 61 is used instead of the heat processing apparatus 60 in the image processing apparatus of FIG.
The hot air blower 61 is heated by applying hot air of a predetermined condition to the image surface of the thermoreversible recording medium, and the color density of the image formed on the thermoreversible recording medium is maximized in the 20 ° C. environment of the image. The color density is adjusted to 88% or more.

In the aspect (3), for example, (i) a method of heating the printer tray itself from which the thermoreversible recording medium is carried out, (ii) a method of providing a heating container covering the periphery of the printer tray, and heating the inside of the heating container, etc. Can be mentioned.
The temperature for heating the printer tray itself in (i) is preferably 30 ° C to 60 ° C.
The temperature at which the inside of the heating container in (ii) is warmed is preferably 20 ° C to 40 ° C.
In the aspect (3), since the discharged thermoreversible recording medium is placed in the heating container and on the printer tray, the time is not particularly limited, but it is necessary to adjust the heating time so that a sufficiently colored state is obtained. It is preferable that heating is performed in a state where the color image density does not decrease due to heating of the heating container.

Here, FIG. 3 is a schematic diagram showing still another example of the image processing apparatus of the present invention. The image processing apparatus of FIG. 3 has the same configuration except that a heating container 62 that covers the printer tray is used instead of the heat processing apparatus 60 in the image processing apparatus of FIG.
Since the inside of the heating container 62 is maintained at 25 ° C., the color density of the image formed on the thermoreversible recording medium is set to 88% or more with respect to the maximum color density of the image in a 20 ° C. environment. Adjusted. The printer tray itself is preferably kept at 30 ° C.

<Other processes and other means>
The conveying step is performed by a conveying unit. The conveying means is not particularly limited as long as it has a function of sequentially conveying the thermoreversible recording medium, and can be appropriately selected according to the purpose. For example, a conveying belt, a conveying roller, a conveying belt and a conveying roller And combinations thereof.

  The control process is not particularly limited as long as it has a function of controlling each process, and each process can be controlled by a control means. Examples of the control means include devices such as a sequencer and a computer.

<Thermal reversible recording medium>
The thermoreversible recording medium is made of a material whose color tone reversibly changes depending on temperature. For example, an electron-donating color-forming compound (hereinafter sometimes referred to as “coloring agent”) and an electron-accepting compound (hereinafter referred to as “color-forming agent”). And a binder resin, a cross-linking agent, and other components as necessary.

  Here, the basic coloring and decoloring phenomenon of the composition comprising the color former and the developer will be described. FIG. 4 shows the relationship between the color density and temperature of this reversible thermosensitive recording medium. When the temperature of the recording medium initially in the decolored state (A) is raised, color development occurs at the temperature T1 at which melting starts, and the molten color state (B) is obtained. When rapidly cooled from the melt color state (B), the color state can be lowered to room temperature and a solid color state (C) is obtained. Whether or not this color development state is obtained depends on the rate of temperature decrease from the molten state, and in slow cooling, the color disappears during the temperature decrease, and the same color disappearance state (A) or rapid color development state (C ) A relatively low concentration state is formed. On the other hand, when the temperature of the rapid color development state (C) is raised again, decoloration occurs at a temperature T2 lower than the color development temperature (D to E), and when the temperature is lowered from here, the same color disappearance state (A) is restored. The actual color developing temperature and color erasing temperature vary depending on the combination of the developer and color former used, and can be selected according to the purpose. Further, the density of the melt coloring state and the coloring density when rapidly cooled are not necessarily the same and may be different.

  In the reversible thermosensitive recording medium, the color development state (C) obtained by quenching from the melted state is a state in which the developer and the color former are mixed in a state where they can contact each other and are in a solid state. Is often formed. This state is a state where the developer and the color former are aggregated to maintain the color development, and it is considered that the color development is stabilized by the formation of this aggregated structure. On the other hand, the decolored state is a state in which both phases are separated. This state is a state in which molecules of at least one compound aggregate to form a domain or crystallize, and the color former and developer are separated and stabilized by aggregation or crystallization. It is done. In many cases, more complete color erasure occurs due to phase separation of the two and crystallization of the developer. In both the decolorization by slow cooling from the melted state shown in FIG. 4 and the decoloration by heating from the colored state, the aggregation structure changes at this temperature, and phase separation and crystallization of the developer occur.

  In the reversible thermosensitive recording medium of the present invention, color recording may be formed by heating to a temperature at which it is once melt-mixed by a thermal head or the like and then rapidly cooling. Further, decolorization is two methods, a method of slowly cooling from a heated state and a method of heating to a temperature slightly lower than the coloring temperature. However, they are the same in the sense that they are phase-separated or at least temporarily held at a temperature at which one crystallizes. The reason for rapid cooling in the formation of the colored state is to prevent the temperature from being maintained at this phase separation temperature or crystallization temperature. The rapid cooling and slow cooling here are relative to one composition, and the boundary thereof changes depending on the combination of the color former and the developer.

  The thermoreversible recording medium used in the image processing method of the present invention comprises at least a support and a thermoreversible recording layer, and further appropriately selected as necessary, a protective layer, an intermediate layer, an undercoat It has other layers such as a layer, a back layer, a photothermal conversion layer, an adhesive layer, an adhesive layer, a colored layer, an air layer, and a light reflecting layer. Each of these layers may have a single layer structure or a laminated structure.

-Support-
The support is not particularly limited in its shape, structure, size and the like, and can be appropriately selected according to the purpose. Examples of the shape include a flat plate shape, May have a single-layer structure or a laminated structure, and the size may be appropriately selected according to the size of the thermoreversible recording medium.

Examples of the material for the support include inorganic materials and organic materials.
Examples of the inorganic material include glass, quartz, silicon, silicon oxide, aluminum oxide, SiO ₂ and metal.
Examples of the organic material include paper, cellulose derivatives such as cellulose triacetate, synthetic paper, polyethylene terephthalate, polycarbonate, polystyrene, polymethyl methacrylate, and the like.
The said inorganic material and the said organic material may be used individually by 1 type, and may use 2 or more types together. Among these, organic materials are preferable, films of polyethylene terephthalate, polycarbonate, polymethyl methacrylate, and the like are preferable, and polyethylene terephthalate is particularly preferable.

For the purpose of improving the adhesion of the coating layer, the support is subjected to surface modification by performing corona discharge treatment, oxidation reaction treatment (chromic acid, etc.), etching treatment, easy adhesion treatment, antistatic treatment, etc. Is preferred.
Moreover, it is preferable to make it white by adding a white pigment such as titanium oxide to the support.
There is no restriction | limiting in particular as thickness of the said support body, Although it can select suitably according to the objective, 10 micrometers-2,000 micrometers are preferable, and 50 micrometers-1,000 micrometers are more preferable.

-Thermoreversible recording layer-
The thermoreversible recording layer (hereinafter sometimes simply referred to as “recording layer”) includes at least a material whose color tone reversibly changes depending on temperature, and further includes other components as necessary. .
The material whose color tone reversibly changes depending on the temperature is a material capable of expressing a phenomenon that causes a visible change reversibly due to temperature change, and due to the difference in heating temperature and cooling rate after heating, It can be changed between a relatively colored state and a decolored state. In this case, the visible change is divided into a color state change and a shape change. The change in the color state is caused by, for example, changes in transmittance, reflectance, absorption wavelength, scattering degree, etc., and the thermoreversible recording medium actually changes in color state due to a combination of these changes. To do.

The material whose color tone reversibly changes depending on the temperature is not particularly limited and can be appropriately selected from known materials. However, the temperature can be easily controlled and high contrast can be obtained. Particularly preferred are those whose color tone reversibly changes between the first specific temperature and the second specific temperature.
Specifically, it may be composed of the leuco dye and the reversible developer, which develops color at a second specific temperature and decolors at the first specific temperature. The leuco dye is itself a colorless or light dye precursor. The leuco dye is not particularly limited and may be appropriately selected from known ones. For example, triphenylmethane phthalide, triallyl methane, fluorane, phenothiazine, thioferolane, xanthene Preferable examples include leuco compounds such as phthalocyanine, indophthalyl, spiropyran, azaphthalide, chromenopyrazole, methine, rhodamine anilinolactam, rhodamine lactam, quinazoline, diazaxanthene, and bislactone. Among these, a fluoran-based or phthalide-based leuco dye is particularly preferable in terms of excellent color development / decoloring properties, color, storage stability, and the like. These may be used individually by 1 type, may use 2 or more types together, and can also respond | correspond to multi-color and full color by laminating | stacking the layer which color-emits a different color tone.

The reversible developer is not particularly limited as long as it can reversibly develop and decolorize by using heat as a factor, and can be appropriately selected according to the purpose. For example, (1) A structure having a color developing ability for developing the leuco dye (for example, phenolic hydroxyl group, carboxylic acid group, phosphoric acid group, etc.), and (2) a structure for controlling cohesion between molecules (for example, long-chain hydrocarbon) Preferred examples include compounds having one or more structures selected from the group wherein the groups are linked to each other in the molecule. The linking moiety may be connected to a divalent or higher valent linking group containing a heteroatom, and the long-chain hydrocarbon group also contains at least one of the same linking group and aromatic group. May be.
Phenol is particularly preferred as the structure having the ability to develop (1) the color of the leuco dye.
The (2) structure for controlling the cohesive force between molecules is preferably a long chain hydrocarbon group having 8 or more carbon atoms, more preferably 11 or more, and the upper limit of the carbon number is 40 or less. Preferably, 30 or less is more preferable.

  Among the reversible developers, a phenol compound represented by the following general formula (1) is preferable, and a phenol compound represented by the following general formula (2) is more preferable.

In the general formulas (1) and (2), R ¹ represents a single bond or an aliphatic hydrocarbon group having 1 to 24 carbon atoms. R ² represents an aliphatic hydrocarbon group having 2 or more carbon atoms which may have a substituent, and the number of carbon atoms is preferably 5 or more, and more preferably 10 or more. R ³ represents an aliphatic hydrocarbon group of 1 to 35 carbon atoms, and carbon number, preferably 6 to 35, 8 to 35 is more preferable. These aliphatic hydrocarbon groups may be used alone or in combination of two or more.
The sum of the carbon numbers of R ¹ , R ² , and R ³ is not particularly limited and may be appropriately selected depending on the purpose. However, the lower limit is preferably 8 or more, more preferably 11 or more. Preferably, the upper limit is preferably 40 or less, and more preferably 35 or less.
If the sum of the carbon numbers is less than 8, the color development stability and decoloring property may be lowered.
The aliphatic hydrocarbon group may be linear or branched, and may have an unsaturated bond, but is preferably linear. In addition, examples of the substituent bonded to the hydrocarbon group include a hydroxyl group, a halogen atom, and an alkoxy group.
X and Y may be the same or different and each represents a divalent group containing an N atom or an O atom. Specific examples include an oxygen atom, an amide group, a urea group, and a diacylhydrazine. Group, oxalic acid diamide group, acylurea group and the like. Among these, an amide group and a urea group are preferable.
n shows the integer of 0-1.

  The reversible developer is preferably used in combination with a compound having at least one —NHCO— group and —OCONH— group in the molecule as a decoloring accelerator. In this case, in the process of forming the decolored state, an intermolecular interaction is induced between the decoloring accelerator and the reversible developer, and the color development / decoloring characteristics are improved.

As a mixing ratio of the leuco dye and the reversible developer, an appropriate range varies depending on the combination of the compounds to be used and cannot be specified unconditionally, but the molar ratio is about the leuco dye 1. The reversible developer is preferably from 0.1 to 20, and more preferably from 0.2 to 10.
When the reversible developer is less than 0.1 or more than 20, the density of the colored state may be lowered.
Moreover, when adding the said decoloring accelerator, the addition amount is preferably 0.1 parts by mass to 300 parts by mass with respect to 100 parts by mass of the reversible developer, and more preferably 3 parts by mass to 100 parts by mass. preferable.
In addition, the leuco dye and the reversible developer can be used in a microcapsule.

  In addition to these components, the thermoreversible recording layer includes a binder resin, a crosslinking agent, and the like, and further includes other components as necessary.

The binder resin is not particularly limited as long as the recording layer can be bound on the support, and at least one resin appropriately selected from known resins can be mixed and used.
As the binder resin, a resin that can be cured by heat, ultraviolet rays, electron beams, or the like is preferable in order to improve durability during repetition, and a thermosetting resin using an isocyanate compound or the like as a crosslinking agent is particularly preferable. .
Examples of the thermosetting resin include a resin having a group that reacts with a crosslinking agent such as a hydroxyl group or a carboxyl group, or a resin obtained by copolymerizing a monomer having a hydroxyl group, a carboxyl group, or the like with another monomer. Can be mentioned.
There is no restriction | limiting in particular as such a thermosetting resin, According to the objective, it can select suitably, For example, a phenoxy resin, polyvinyl butyral resin, cellulose acetate propionate resin, cellulose acetate butyrate resin, acrylic polyol Examples thereof include a resin, a polyester polyol resin, and a polyurethane polyol resin. These may be used alone or in combination of two or more. Among these, acrylic polyol resin, polyester polyol resin, and polyurethane polyol resin are particularly preferable.

  The mixing ratio (mass ratio) of the leuco dye and the binder resin in the recording layer is preferably 0.1 to 10 with respect to the leuco dye 1. If the binder resin is less than 0.1, the thermal strength of the recording layer may be insufficient, and if it exceeds 10, the color density may decrease.

  There is no restriction | limiting in particular as said crosslinking agent, According to the objective, it can select suitably, For example, isocyanate, amino resin, a phenol resin, amines, an epoxy compound, etc. are mentioned. Among these, isocyanates are preferable, and polyisocyanate compounds having a plurality of isocyanate groups are particularly preferable.

  The amount of the crosslinking agent added to the binder resin is preferably 0.01 to 2 in terms of the ratio of the functional group of the crosslinking agent to the number of active groups contained in the binder resin. If the ratio of the functional groups is less than 0.01, the heat strength may be insufficient, and if it exceeds 2, the color development and decoloring characteristics may be adversely affected.

Furthermore, you may use the catalyst used for this kind of reaction as a crosslinking accelerator.
Examples of the crosslinking accelerator include tertiary amines such as 1,4-diazabicyclo [2,2,2] octane, and metal compounds such as organotin compounds.
The gel fraction of the thermosetting resin when thermally crosslinked is preferably 30% or more, more preferably 50% or more, and even more preferably 70% or more. When the gel fraction is less than 30%, the crosslinked state is not sufficient and the durability may be inferior.

  As a method for distinguishing whether the binder resin is in a crosslinked state or in a non-crosslinked state, for example, it can be distinguished by immersing the coating film in a highly soluble solvent. That is, the binder resin in the non-crosslinked state is dissolved in the solvent and does not remain in the solute.

  Examples of other components in the recording layer include various additives for improving and controlling coating characteristics, color development and decoloring characteristics. Examples of these additives include surfactants, plasticizers, conductive agents, fillers, antioxidants, light stabilizers, color development stabilizers, and decolorization accelerators.

A method for producing the recording layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, (1) the binder resin, the leuco dye, and the reversible developer are contained in a solvent. A method of coating the recording layer coating solution dissolved or dispersed in the support on the support and evaporating the solvent to form a sheet or the like, or thereafter crosslinking, (2) only the binder resin At the same time as coating the recording layer coating liquid in which the leuco dye and the reversible developer are dispersed in a solvent in which the solvent is dissolved, and by evaporating the solvent to form a sheet or the like, Or (3) without using a solvent, the binder resin, the leuco dye and the reversible developer are heated and melted and mixed together, and the molten mixture is formed into a sheet or the like. One that crosslinks after cooling , And the like.
In these, a sheet-like thermoreversible recording medium can be formed without using the support. In addition, the recording layer coating liquid may be prepared by dispersing each material in a solvent using a dispersing device, or may be individually dispersed in a solvent and mixed together. The material may be deposited by cooling.

There is no restriction | limiting in particular as a solvent used in (1) or (2) in the preparation methods of the said recording layer, Although it can select suitably according to the objective, The said binder resin, the said leuco dye, and the said reversible appearance Although it differs depending on the type of the colorant and cannot be generally specified, examples thereof include tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, chloroform, carbon tetrachloride, ethanol, toluene, benzene and the like.
The reversible developer is dispersed in the form of particles in the recording layer.

Various pigments, antifoaming agents, pigments, dispersants, slip agents, preservatives, crosslinking agents, plasticizers, and the like are added to the recording layer coating solution for the purpose of developing high performance as a coating material. May be.
The method for coating the recording layer is not particularly limited and may be appropriately selected depending on the purpose. The recording body is conveyed in the form of a roll, continuously, or cut into a sheet, on the support. For example, blade coating, wire bar coating, spray coating, air knife coating, bead coating, curtain coating, gravure coating, kiss coating, reverse roll coating, dip coating, die coating, etc. It can carry out using the well-known method of these.
There is no restriction | limiting in particular as drying conditions of the said coating liquid for recording layers, According to the objective, it can select suitably, For example, about 10 second-about 10 minutes at the temperature of room temperature-140 degreeC etc. are mentioned.
There is no restriction | limiting in particular as thickness of the said recording layer, Although it can select suitably according to the objective, For example, 1 micrometer-20 micrometers are preferable, and 3 micrometers-15 micrometers are more preferable. If the thickness of the recording layer is less than 1 μm, the color density may be low and the contrast of the image may be lowered. If the thickness exceeds 20 μm, the heat distribution in the layer becomes large and the color does not reach the color development temperature. In some cases, a portion that does not occur is generated, and a desired color density cannot be obtained.

-Protective layer-
The protective layer is preferably provided on the recording layer for the purpose of protecting the recording layer.
There is no restriction | limiting in particular as said protective layer, According to the objective, it can select suitably, For example, although you may form in multiple layers, it is preferable to provide in the outermost surface of the layer exposed.
The protective layer contains at least a binder resin, and further contains other components such as a filler, a lubricant, and a coloring pigment as necessary.

The binder resin for the protective layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an ultraviolet (UV) curable resin, a thermosetting resin, an electron beam curable resin, and the like are preferable. Among these, ultraviolet (UV) curable resins and thermosetting resins are particularly preferable.
The UV curable resin can form a very hard film after curing, and can suppress damage due to physical contact with the surface and deformation of the medium due to laser heating, so that thermoreversible recording with excellent repeated durability A medium can be obtained.
In addition, although the thermosetting resin is slightly inferior to the UV curable resin, the surface can be similarly hardened, and a thermoreversible recording medium excellent in repeated durability can be obtained.

  The UV curable resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, vinyl And unsaturated polyester oligomers; monomers such as various monofunctional or polyfunctional acrylates, methacrylates, vinyl esters, ethylene derivatives, and allyl compounds; Among these, tetrafunctional or higher polyfunctional monomers or oligomers are particularly preferable. By mixing two or more of these monomers or oligomers, the hardness, shrinkage, flexibility, coating strength, etc. of the resin film can be appropriately adjusted.

In order to cure the monomer or oligomer using ultraviolet rays, it is preferable to use a photopolymerization initiator or a photopolymerization accelerator.
There is no restriction | limiting in particular as addition amount of the said photoinitiator and the said photoinitiator, Although it can select suitably according to the objective, 0.1 mass with respect to the total mass of the resin component of the said protective layer. % To 20% by mass is preferable, and 1% to 10% by mass is more preferable.

Irradiation of ultraviolet rays for curing the ultraviolet curable resin can be performed using a known ultraviolet irradiation device, and examples of the ultraviolet irradiation device include a light source, a lamp, a power source, a cooling device, a conveyance device, and the like. Etc.
Examples of the light source include a mercury lamp, a metal halide lamp, a potassium lamp, a mercury xenon lamp, and a flash lamp.
The wavelength of the light emitted from the light source is not particularly limited and can be appropriately selected according to the ultraviolet absorption wavelength of the photopolymerization initiator and the photopolymerization accelerator contained in the recording layer.
The irradiation conditions of the ultraviolet rays are not particularly limited and can be appropriately selected according to the purpose.For example, the lamp output, the conveyance speed, etc. can be appropriately determined according to the irradiation energy necessary for crosslinking the resin. That's fine.

For the purpose of ensuring good transportability, a silicone having a polymerizable group, a silicone-grafted polymer, a wax, a mold release agent such as zinc stearate, a lubricant such as silicone oil, and the like can be added.
The amount of these added is preferably 0.01% by mass to 50% by mass and more preferably 0.1% by mass to 40% by mass with respect to the total mass of the resin component of the protective layer.
Even if the addition amount is small, the effect can be expressed, but if it is less than 0.01% by mass, it may be difficult to obtain the effect by addition, and if it exceeds 50% by mass, the adhesion to the lower layer may be obtained. May cause problems.
Further, the protective layer may contain an organic ultraviolet absorber, and the content thereof is preferably 0.5% by mass to 10% by mass with respect to the total mass of the resin component of the protective layer. .

Furthermore, an inorganic filler, an organic filler, or the like may be added to the protective layer in order to improve transportability.
Examples of the inorganic filler include calcium carbonate, kaolin, silica, aluminum hydroxide, alumina, aluminum silicate, magnesium hydroxide, magnesium carbonate, magnesium oxide, titanium oxide, zinc oxide, barium sulfate, and talc. . These may be used individually by 1 type and may use 2 or more types together.
Moreover, it is preferable to use a conductive filler as a countermeasure against static electricity, and it is more preferable to use a needle-like filler as the conductive filler.
As the conductive filler, titanium oxide whose surface is coated with antimony-doped tin oxide is particularly preferable.
As a particle size of the said inorganic filler, 0.01 micrometer-10.0 micrometers are preferable, for example, and 0.05 micrometer-8.0 micrometers are more preferable.
The amount of the inorganic filler added is preferably 0.001 to 2 parts by mass, more preferably 0.005 to 1 part by mass with respect to 1 part by mass of the binder resin in the protective layer.

  There is no restriction | limiting in particular as said organic filler, According to the objective, it can select suitably, For example, a silicone resin, a cellulose resin, an epoxy resin, a nylon resin, a phenol resin, a polyurethane resin, a urea resin, a melamine resin, polyester Examples thereof include resins, polycarbonate resins, styrene resins, acrylic resins, polyethylene resins, formaldehyde resins, polymethyl methacrylate resins, and the like.

The thermosetting resin is preferably cross-linked. Therefore, as the thermosetting resin, for example, those having a group that reacts with a curing agent such as a hydroxyl group, an amino group, and a carboxyl group are preferable, and a polymer having a hydroxyl group is particularly preferable.
In order to improve the strength of the protective layer, the hydroxyl value of the thermosetting resin is preferably 10 mgKOH / g or more, more preferably 30 mgKOH / g or more, and 40 mgKOH / g in that sufficient coating strength can be obtained. g or more is more preferable. By imparting sufficient coating strength, deterioration of the thermoreversible recording medium can be suppressed even when repeated erasing and recording are performed. As the curing agent, for example, the same curing agent as that used in the recording layer can be preferably used.

A conventionally known surfactant, leveling agent, antistatic agent, etc. may be added to the protective layer as required.
Further, a polymer having an ultraviolet absorbing structure (hereinafter, sometimes referred to as “ultraviolet absorbing polymer”) may be used.
Here, the polymer having an ultraviolet absorbing structure means a polymer having an ultraviolet absorbing structure (for example, an ultraviolet absorbing group) in the molecule.
Examples of the ultraviolet absorbing structure include a salicylate structure, a cyanoacrylate structure, a benzotriazole structure, and a benzophenone structure. Among these, a bezotriazole structure and a benzophenone structure are particularly preferable in terms of good light resistance.
There is no restriction | limiting in particular as a polymer which has the said ultraviolet absorption structure, According to the objective, it can select suitably, For example, 2- (2'-hydroxy-5'-methacryloxyethylphenyl) -2H-benzotriazole and A copolymer of 2-hydroxyethyl methacrylate and styrene, a copolymer of 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2-hydroxypropyl methacrylate, and methyl methacrylate, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2-hydroxyethyl methacrylate, methyl methacrylate and t-butyl methacrylate, 2 , 2,4,4-Tetrahydroxybenzophenone, 2-hydroxypropyl methacrylate and styrene And a copolymer of methyl methacrylate and propyl methacrylate. These may be used individually by 1 type and may use 2 or more types together.

  As the solvent, the coating liquid dispersing device, the protective layer coating method, the drying method and the like used in the protective layer coating solution, the known methods described in the preparation of the recording layer can be used. In addition, when using the said ultraviolet curing resin, after apply | coating and drying, the hardening process by ultraviolet irradiation is required, but an ultraviolet irradiation device, a light source, irradiation conditions, etc. are as above-mentioned.

  There is no restriction | limiting in particular as thickness of the said protective layer, Although it can select suitably according to the objective, 0.1 micrometer-20 micrometers are preferable, 0.5 micrometer-10 micrometers are more preferable, 1.5 micrometers-6 micrometers are still more preferable. . When the thickness is less than 0.1 μm, the function as a protective layer of the thermoreversible recording medium cannot be sufficiently exerted, and it is deteriorated immediately due to repeated history due to heat and can be used repeatedly. If the thickness exceeds 20 μm, sufficient heat cannot be transmitted to the recording layer below the protective layer, and image recording and erasure due to heat may not be sufficiently performed.

-Intermediate layer-
The intermediate layer improves adhesion between the recording layer and the protective layer, prevents alteration of the recording layer by application of the protective layer, prevents migration of additives in the protective layer to the recording layer, etc. For the purpose, it is preferably provided between the two. In this case, the storage stability of the color image can be improved.
The protective layer contains at least a binder resin, and further contains other components such as a filler, a lubricant, and a coloring pigment as necessary.

There is no restriction | limiting in particular as binder resin of the said intermediate | middle layer, According to the objective, it can select suitably, Resin components, such as binder resin in the said recording layer, a thermoplastic resin, and a thermosetting resin, can be used.
Examples of the binder resin include polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl alcohol resin, polyvinyl butyral resin, polyurethane resin, saturated polyester resin, unsaturated polyester resin, epoxy resin, phenol resin, polycarbonate resin, and polyamide resin. Can be mentioned.

The intermediate layer preferably contains an ultraviolet absorber. There is no restriction | limiting in particular as this ultraviolet absorber, According to the objective, it can select suitably, For example, both an organic compound and an inorganic compound can be used.
The organic and inorganic ultraviolet absorbers may be contained in the recording layer.
Further, an ultraviolet absorbing polymer may be used, and it may be cured with a crosslinking agent. These are preferably the same as those used in the protective layer.

There is no restriction | limiting in particular as thickness of the said intermediate | middle layer, Although it can select suitably according to the objective, 0.1 micrometer-20 micrometers are preferable, and 0.5 micrometer-5 micrometers are more preferable.
As the solvent used in the intermediate layer coating liquid, the coating liquid dispersion device, the intermediate layer coating method, the intermediate layer drying method, and the curing method, the known methods described in the preparation of the recording layer may be used. it can.

-Under layer-
In order to effectively utilize the applied heat to increase the sensitivity, or to improve the adhesion between the support and the recording layer and to prevent the recording layer material from penetrating into the support, the recording layer and the recording layer An under layer may be provided between the support and the support.
The under layer contains at least hollow particles, and contains a binder resin and, if necessary, other components.

Examples of the hollow particles include single hollow particles in which one hollow portion is present in the particles, and multi-hollow particles in which many hollow portions are present in the particles. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular as a material of the said hollow particle, Although it can select suitably according to the objective, For example, a thermoplastic resin etc. are mentioned suitably.
The hollow particles may be appropriately manufactured or commercially available.
There is no restriction | limiting in particular as the addition amount in the said under layer of the said hollow particle, Although it can select suitably according to the objective, For example, 10 mass%-80 mass% are preferable.

As the binder resin for the under layer, the same resin as that for the recording layer or the layer containing a polymer having an ultraviolet absorbing structure can be used.
The under layer may contain at least one of inorganic fillers such as calcium carbonate, magnesium carbonate, titanium oxide, silicon oxide, aluminum hydroxide, kaolin, and talc, and various organic fillers.
In addition, the under layer may further contain a lubricant, a surfactant, a dispersant, and the like.
There is no restriction | limiting in particular as thickness of the said under layer, Although it can select suitably according to the objective, 0.1 micrometers-50 micrometers are preferable, 2 micrometers-30 micrometers are more preferable, and 12 micrometers-24 micrometers are still more preferable.

-Back layer-
A back layer may be provided on the side of the support opposite to the surface on which the recording layer is provided in order to prevent curling, antistatic and transportability of the thermoreversible recording medium.
The back layer contains at least a binder resin, and further contains other components such as a filler, a conductive filler, a lubricant, and a coloring pigment as necessary.

There is no restriction | limiting in particular as binder resin of the said back layer, According to the objective, it can select suitably, For example, a thermosetting resin, an ultraviolet-ray (UV) curable resin, an electron beam curable resin etc. are mentioned. . Among these, ultraviolet (UV) curable resins and thermosetting resins are particularly preferable.
About the said ultraviolet curable resin and the said thermosetting resin, the thing similar to what is used with the said recording layer, the said protective layer, and the said intermediate | middle layer can be used conveniently. The same applies to the filler, the conductive filler, and the lubricant.

-Photothermal conversion layer-
When performing laser recording, a photothermal conversion layer may be provided as necessary.
The photothermal conversion layer is a layer having a function of absorbing laser light and generating heat, and contains at least a photothermal conversion material having a role of absorbing laser light and generating heat.
The photothermal conversion material can be roughly classified into an inorganic material and an organic material.
Examples of the inorganic material include carbon black, metals such as Ge, Bi, In, Te, Se, and Cr, and alloys containing them, and these include vacuum deposition methods and particulate materials. A layer is formed by bonding with a resin or the like.
As the organic material, various dyes can be appropriately used depending on the wavelength of light to be absorbed. When a semiconductor laser is used as the light source, a near infrared having an absorption peak in the vicinity of 700 to 1,500 nm. Absorbing dyes are used. Specific examples include cyanine dyes, quinone dyes, quinoline derivatives of indonaphthol, phenylenediamine nickel complexes, phthalocyanine dyes, naphthalocyanine dyes, and the like. In order to repeat image recording and erasing, it is preferable to select a photothermal conversion material having excellent heat resistance.
The near-infrared absorbing dyes may be used alone or in combination of two or more, and may be mixed in the recording layer. In this case, the recording layer also serves as the photothermal conversion layer.
When the photothermal conversion layer is provided, the photothermal conversion material is usually used in combination with a resin. The resin used for the light-to-heat conversion layer is not particularly limited and can be appropriately selected from known ones that can hold the inorganic material and the organic material. A curable resin or the like is preferable.

-Adhesive layer and adhesive layer-
The thermoreversible recording medium can be obtained in the form of a thermoreversible recording label by providing an adhesive layer or an adhesive layer on the opposite surface of the support to the recording layer forming surface.
There is no restriction | limiting in particular as a material of the said contact bonding layer and the said adhesion layer, According to the objective, it can select suitably from what is generally used.

The material of the adhesive layer and the adhesive layer may be a hot melt type. Moreover, a release paper may be used and a non-release paper type may be used. By providing the adhesive layer or the pressure-sensitive adhesive layer in this manner, the recording layer can be attached to the entire surface or a part of a thick substrate such as a magnetic stripe-added PVC card that is difficult to apply the recording layer. This improves the convenience of the thermoreversible recording medium, such as being able to display part of the information stored in the magnetism.
A thermoreversible recording label provided with such an adhesive layer or adhesive layer is also suitable for thick cards such as IC cards and optical cards.

-Colored layer-
The thermoreversible recording medium may be provided with a colored layer between the support and the recording layer for the purpose of improving visibility.
The colored layer can be formed by applying a solution or dispersion containing a colorant and a resin binder to a target surface and drying, or simply bonding a colored sheet.

The colored layer can be a color print layer.
Examples of the colorant in the color printing layer include various dyes and pigments contained in color inks used in conventional full color printing.
Examples of the resin binder include various thermoplastic resins, thermosetting resins, ultraviolet curable resins, and electron beam curable resins.
There is no restriction | limiting in particular as thickness of the said color printing layer, Since it changes suitably with respect to printing color density, it can select according to desired printing color density.

The thermoreversible recording medium may be used in combination with an irreversible recording layer. In this case, the color tone of each recording layer may be the same or different.
In addition, a part of the same surface as the recording layer of the thermoreversible recording medium, a part of the entire surface, or a part of the opposite surface may be printed with offset printing, gravure printing, or an arbitrary pattern by an inkjet printer, a thermal transfer printer, a sublimation printer, or the like. In addition, an OP varnish layer mainly composed of a curable resin may be provided on a part or the entire surface of the colored layer.
Examples of the pattern include characters, patterns, patterns, photographs, information detected by infrared rays, and the like.
It is also possible to add a dye or pigment to any one of the simply configured layers for coloring.
Further, the thermoreversible recording medium can be provided with a hologram for security. In addition, in order to impart design properties, it is possible to provide a relief image, an intaglio shape, or a design such as a person image, a company emblem, or a symbol mark.

-Shape and application of thermoreversible recording medium-
The thermoreversible recording medium can be processed into a desired shape according to the application, for example, a card shape, a tag shape, a label shape, a sheet shape, a roll shape, or the like.
Moreover, what was processed into the card form can be applied to a prepaid card, a point card, and further a credit card.
Furthermore, a tag-shaped size smaller than the card size can be used for a price tag or the like, and a tag-shaped size larger than the card size can be used for process management, a shipping instruction, a ticket, or the like.
Since the label can be affixed, it is processed into various sizes and can be affixed to carts, containers, boxes, containers, etc. that are repeatedly used and used for process management, article management, and the like. In addition, since the recording range is wide at a sheet size larger than the card size, it can be used for general documents, process management instructions, and the like.

-Example of combination with thermoreversible recording member and RF tag-
The thermoreversible recording member includes the thermoreversible recording layer (recording layer) capable of reversible display and an information storage unit provided in (integrated with) the same card or tag, and a part of information stored in the information storage unit Is displayed on the recording layer, information can be confirmed simply by looking at a card or tag without a special device, which is excellent in convenience. Further, when the contents of the information storage unit are rewritten, the thermoreversible recording medium can be used repeatedly many times by rewriting the display of the thermoreversible recording unit.
The information storage unit is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a magnetic recording layer, a magnetic stripe, an IC memory, an optical memory, and an RF tag. When used for process management, article management, etc., an RF tag can be used particularly preferably.
The RF tag includes an IC chip and an antenna connected to the IC chip.

The thermoreversible recording member includes the recording layer capable of reversible display and an information storage unit, and a suitable example of the information storage unit is an RF tag.
FIG. 3 shows an example of a schematic diagram of an RF tag. The RF tag 85 includes an IC chip 81 and an antenna 82 connected to the IC chip 81. The IC chip 81 is divided into four parts: a storage unit, a power supply adjustment unit, a transmission unit, and a reception unit, and each performs communication by sharing the function. In the communication, the antenna between the RF tag 85 and the reader / writer communicates by radio waves to exchange data. Specifically, there are two types: an electromagnetic induction method in which an antenna of the RF tag 85 receives a radio wave from a reader / writer and generates electromotive force by electromagnetic induction by a resonance action, and a radio wave method activated by a radiated electromagnetic field. In both cases, the IC chip 81 in the RF tag 85 is activated by an external electromagnetic field, converts the information in the chip into a signal, and then transmits a signal from the RF tag 85. This information is received by the antenna on the reader / writer side and recognized by the data processing device, and data processing is performed on the software side.

Examples of a method for integrating the thermoreversible recording medium and the RF tag include a method of attaching the RF tag to a part of the thermoreversible recording medium and a method of incorporating the RF tag inside the thermoreversible recording medium.
When attaching the FR tag, it may be attached anywhere as long as it is a part of the thermoreversible recording medium, but it is particularly preferable to apply it to the surface of the antistatic layer. The method of affixing can be affixed with a general pressure-sensitive adhesive or adhesive.
In the case where the RF tag is incorporated in the thermal recording medium, it is preferable that the RF tag is sandwiched between a support made of at least a thermoreversible recording medium and the other support or support member via a bonding member. The bonding member in this case is not particularly limited as long as the supports can be bonded to each other, but a general film or resin may be used, or a general adhesive or adhesive may be used for bonding. A general hot melt agent may be used. In the case of using a hot melt agent, the RF tag can be sandwiched between the previous supports and processed by applying pressure or heat.
Various forms of thermoreversible recording media, for example, card tags and smaller ones are used for apparel, prize tags attached to products, etc., and used for product management applications attached to small members and small containers Applications include cards, prepaid cards, and games and games. A Kanban size larger than the card size can be suitably used for process management, physical distribution management, and the like, and a sheet size of A5 size or larger can also be used for general documents, process management instructions, and the like. Furthermore, since no dust or dust is generated, it can be used in a clean room or the like.

An example of how to use the thermoreversible recording member that combines the thermoreversible recording medium and the RF tag in process management will be described.
The process line in which the containers containing the delivered raw materials are transported is equipped with means for writing a visible image in a non-contact manner on the display part while being transported, and means for non-contact erasing, and transmission of electromagnetic waves. A reader / writer for reading and rewriting information of the RF tag provided in the container without contact is provided. In addition, the process line is provided with a control means for automatically branching, weighing, managing, etc. on the physical distribution line using the individual information read and written without contact while the container is being conveyed. ing.
Information such as article name and quantity is recorded on the thermoreversible recording medium and the RF tag with respect to the thermoreversible recording medium with the RF tag attached to the container, and inspection is performed. In the next process, a processing instruction is given to the delivered raw material, information is recorded on the thermoreversible recording medium and the RF tag, and a processing instruction sheet is obtained and the process proceeds to the processing process. Next, order information is recorded in the thermoreversible recording medium and the RF tag as an ordering instruction for the processed product, the shipping information is read from the container collected after the product is shipped, and the delivery container and the RF tag are attached again. Used as a thermoreversible recording medium.
At this time, since non-contact recording is performed on the thermoreversible recording medium using a laser, information can be erased and recorded without peeling the thermoreversible recording medium from a container or the like. Since information can be recorded by contact, the process can be managed in real time, and information in the RF tag can be simultaneously displayed on the thermoreversible recording medium.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Production Example 1)
<Preparation of thermoreversible recording medium>
A thermoreversible recording medium in which the color tone changes reversibly (decolored state-colored state) depending on the temperature was produced as follows.

-Support-
As the support, a white polyester film having a thickness of 125 μm (Tetron film U2L98W, manufactured by Teijin DuPont Co., Ltd.) was used.

-Under layer-
30 parts by mass of a styrene-butadiene copolymer (manufactured by Nippon A & L Co., PA-9159), 12 parts by mass of a polyvinyl alcohol resin (manufactured by Kuraray Co., Ltd., Poval PVA103), hollow particles (manufactured by Matsumoto Yushi Co., Ltd., Microsphere R) -300) 20 mass parts and 40 mass parts of water were added, and it stirred for 1 hour until it became a uniform state, and prepared the underlayer coating liquid.
Next, the obtained under layer coating solution was applied onto the support with a wire bar, heated and dried at 80 ° C. for 2 minutes, and an under layer having a thickness of 20 μm was recorded.

-Thermoreversible recording layer (recording layer)-
5 parts by mass of a reversible developer represented by the following structural formula (1), and 0.5 parts by mass of two types of decoloring accelerators represented by the following structural formulas (2) and (3) 10 parts by mass of a polyol 50% by mass solution (hydroxyl value = 200 mg KOH / g) and 80 parts by mass of methyl ethyl ketone were pulverized and dispersed using a ball mill until the average particle size became 1 μm.

--Reversible developer--

--Decolorization accelerator ---

  Next, 1 part by mass of 2-anilino-3-methyl-6dibutylaminofluorane as the leuco dye is represented by the following structural formula (4) in a dispersion obtained by pulverizing and dispersing the reversible developer. Add 0.2 parts by mass of a phenolic antioxidant (Ciba Specialty Chemicals, IRGANOX565) and 5 parts by mass of isocyanate (Nihon Polyurethane Co., Ltd., Coronate HL). Prepared.

  Next, the recording layer coating liquid thus obtained was applied onto the above-mentioned underlayer-recorded support using a wire bar, dried at 100 ° C. for 2 minutes, and then cured at 60 ° C. for 24 hours. And a recording layer having a thickness of 13 μm was recorded.

-Intermediate layer-
Acrylic polyol resin 50 mass% solution (Mitsubishi Rayon Co., Ltd., LR327) 3 mass parts, Zinc oxide fine particle 30 mass% dispersion (Sumitomo Cement Co., Ltd., ZS303) 7 mass parts, Isocyanate (Nihon Polyurethane Co., Ltd., Coronate HL) 1.5 parts by mass and 7 parts by mass of methyl ethyl ketone were added and stirred well to prepare an intermediate layer coating solution.
Next, on the support on which the under layer and the recording layer are recorded, the intermediate layer coating solution is applied with a wire bar, heated and dried at 90 ° C. for 1 minute, and then at 60 ° C. Heated for 2 hours and recorded a 2 μm thick intermediate layer.

-Protective layer-
3 parts by mass of pentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPHA), 3 parts by mass of urethane acrylate oligomer (manufactured by Negami Kogyo Co., Ltd., Art Resin UN-3320HA), acrylic ester of dipentaerythritol caprolactone ( Nippon Kayaku Co., Ltd., KAYARAD DPCA-120) 3 parts by mass, silica (Mizusawa Chemical Co., Ltd., P-526) 1 part by mass, photopolymerization initiator (Nippon Ciba Geigy Co., Ltd., Irgacure 184) 0.5 Mass parts and 11 parts by mass of isopropyl alcohol were added, and the mixture was well stirred by a ball mill and dispersed until the average particle size became about 3 μm to prepare a coating solution for a protective layer.
Next, on the support on which the under layer, the recording layer, and the intermediate layer are recorded, the protective layer coating solution is applied with a wire bar, heated and dried at 90 ° C. for 1 minute, A protective layer having a thickness of 4 μm was recorded by crosslinking with an 80 W / cm ultraviolet lamp.

-Back layer-
Pentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD DPHA) 7.5 parts by mass, urethane acrylate oligomer (manufactured by Negami Kogyo Co., Ltd., Art Resin UN-3320HA) 2.5 parts by mass, acicular conductive titanium oxide ( FT-3000 manufactured by Ishihara Sangyo Co., Ltd., long axis = 5.15 μm, short axis = 0.27 μm, composition: 2.5 parts by mass of titanium oxide coated with antimony-doped tin oxide, photopolymerization initiator (Nippon Ciba-Geigy Corporation) Manufactured, Irgacure 184) and 0.5 parts by mass of isopropyl alcohol and 13 parts by mass of isopropyl alcohol were added, and the mixture was thoroughly stirred with a ball mill to prepare a coating solution for a back layer.
Next, the back layer coating liquid is applied with a wire bar on the surface of the support on which the recording layer, the intermediate layer, and the protective layer are recorded, on the side where these layers are not recorded. After heating and drying at 90 ° C. for 1 minute, crosslinking was performed with an 80 W / cm ultraviolet lamp to record a back layer having a thickness of 4 μm. Thus, the thermoreversible recording medium of Production Example 1 was produced.

(Production Example 2)
Two white polyester films (Lumirror E20, manufactured by Toray Industries, Inc.) having a thickness of 100 μm were used as the support. On one support, the recording layer thickness was 10.5 μm in Production Example 1, and the back layer was provided on the other support.
A hot melt sheet is stacked between the two unsupported surfaces of the above two supports so that the RF tag is sandwiched from both sides, and the laminate is heated at 1 kg / cm ² , 130 ° C. for 10 seconds, and the total thickness is 560 μm. A thermoreversible recording medium was produced.

Example 1
−Adjustment of ambient temperature−
Using the thermoreversible recording medium of Production Examples 1 and 2, a simulator having a rewritable printer function (manufactured by Wedge Co., Ltd.) is heated as a heat treatment device on the conveyance path for conveying the thermoreversible recording medium after image formation to the printer tray. The following experiment was performed using the device in which the device was installed. The simulator includes a thermal head (manufactured by Toshiba Hokuto Corporation) as image forming means and an erasing device (manufactured by Wedge Corporation) as image erasing means.
Ambient temperature of the thermoreversible recording medium after image formation (Ambient temperature is created using a low-humidity constant temperature and humidity chamber ESPEC PDL-4KP, and the surrounding environment is measured with a Digifull thermo-hygrometer TRH-CA) Is recorded at 5 ° C., 10 ° C., 15 ° C., and 20 ° C., and a test pattern image (solid image, character image) is recorded. The color density was measured using a spectroscopic color densitometer (X-Rite Model 938, manufactured by X-Rite). Further, the color development rate, which is a ratio to the maximum color density at an environmental temperature of 20 ° C., was determined. The results are shown in Table 1 and FIGS. The heat treatment apparatus after printing is turned off.
Next, the sample developed in each environment using the simulator was erased at a transport speed of 156 mm / sec in each environment where the color was developed. The unerased density of the solid image portion of the test pattern after erasure was measured with a spectroscopic color densitometer (X-Rite Model 938, manufactured by X-Rite). The unerased density is shown as a difference between the density of the erased portion of the solid image and the density of the surrounding background portion. The results are shown in Table 1 and FIG. Note that when the unerased density is below 0.020, the unerased residue is hardly visible.
[Eraseability standards]
The unerased density is less than 0.020. O: The erased density is sufficiently erased. The erased density is 0.020 to 0.050.
Unerasable density is 0.050 or more. X: Unerasable residue is conspicuous and erasability is insufficient.

  From the results of Table 1 and FIGS. 6 to 8, the erasability is markedly unsatisfactory in an environment of 5 ° C., and the unerasable density is low in an environment of 10 ° C., but the erasability is insufficient. It was found that the erasability with an unerasable density of 0.02 or less was sufficiently satisfied under an environment of 15 ° C.

(Example 2)
-Adjustment of erase speed-
Using the thermoreversible recording medium of Production Example 2 and using the simulator of Example 1 to create the ambient temperature (using the low-humidity constant temperature and humidity chamber ESPEC PDL-4KP, Measure color density and unerased density at 5 ° C, 10 ° C, and 15 ° C by changing the erasing speed to 52mm / sec, 104mm / sec, and 156mm / sec at 5 ° C, 10 ° C, and 15 ° C. did. The results are shown in Table 2. The heat treatment apparatus after printing is turned off.
In a low temperature environment, the erasability at high speed becomes insufficient, and in particular in a 5 ° C. environment, erasing cannot be performed unless it is 52 mm / sec.

(Example 3)
-Adjustment of heating conditions-
Using the thermoreversible recording media of Production Examples 1 and 2, using the same simulator as in Example 1, erasing printing, heating, and erasing were performed under the following printing conditions, heating conditions, and erasing conditions. Specifically, the ambient temperature of the thermoreversible recording medium after image formation (the ambient temperature is created using a low-humidity constant temperature and humidity chamber ESPEC PDL-4KP, and the surrounding environment is converted into a digital full thermo-hygrometer TRH- Erase printing was carried out under the following printing conditions under the condition of 5 ° C. (measured by CA), and heated to the temperature shown in Table 3 below at a rate of 52 mm / sec with a heat treatment device of the simulator 4 seconds after printing. Thereafter, the medium left for 5 minutes was erased at 156 mm / sec at 165 ° C. The results are shown in Table 3.
The maximum color density at 20 ° C. of the thermoreversible recording medium of Production Example 1 was 1.44, and the maximum color density at 20 ° C. of the thermoreversible recording medium of Production Example 2 was 1.32.

−Printing conditions−
Printing speed: 52mm / sec
Printing energy: 250mW / dot
Thermal head: 300 dpi
Resistance value: 1911Ω
-Heating conditions-
Conveying speed: 52mm / sec
Heating head: Erase device 4 seconds after printing-Erase conditions-
Erase speed: 156mm / sec
Heating head: Erase device Erase temperature: 165 ° C

From the results in Table 3, it was found that the color density in a 5 ° C. environment was increased due to the effect of heating. Correspondingly, it was found that the unerased density in the erased portion was lowered. However, when a higher temperature is applied, the color density decreases. This is presumably because the thermoreversible recording medium was heated to a high temperature at the time of color development and gradually cooled after the color development, so that the density was lowered because part of the color development was in the erase mode.
It was found that the color density increased due to the heating effect, and the high-speed erasability was improved accordingly.

Example 4
-Adjustment of heating conditions-
Using the thermoreversible recording mediums of Production Examples 1 and 2, the heating device part, which is the heating device part of the simulator used in Example 1, was removed, and a hot air generator was attached as a heating device to the discharge port after printing. Erase printing, heating, and erasing were performed under the printing conditions, heating conditions, and erasing conditions.
Specifically, the ambient temperature of the thermoreversible recording medium after image formation (the ambient temperature is created using a low-humidity constant temperature and humidity chamber ESPEC PDL-4KP, and the surrounding environment is converted into a digital full thermo-hygrometer TRH- Erasing and printing is performed under the following printing conditions with 5 ° C (measured by CA), a hot air generator is attached to the discharge port after printing, and the medium conveyed at a speed of 52 mm / sec is heated with hot air did. The heating temperature was 60 ° C. at the outlet of the hot air generator. Thereafter, erasing was performed at 156 mm / sec and 165 ° C. after 5 minutes. The results are shown in Table 4.
The maximum color density at 20 ° C. of the thermoreversible recording medium of Production Example 1 was 1.44, and the maximum color density at 20 ° C. of the thermoreversible recording medium of Production Example 2 was 1.32.
−Printing conditions−
Printing speed: 52mm / sec
Printing energy: 250mW / dot
Thermal head: 300 dpi
Resistance value: 1911Ω
-Heating conditions-
Conveying speed: 52mm / sec
Heating device: Hot air generator-Erase condition-
Erase speed: 156mm / sec
Heating head: Erase device Erase temperature: 165 ° C

From the results in Table 4, it was found that the color density in a 5 ° C. environment increased by applying warm air to the outlet, and the unerased density after erasing decreased.

(Example 5)
-Adjustment of heating conditions-
Using the thermoreversible recording media of Production Examples 1 and 2, remove the warm air generator, which is the heating device of the simulator used in Example 4, cover the printer tray of the discharge port with a case, and install a heater under the tray The provided heating apparatus was attached and erasure printing, heating, and erasing were performed under the following printing conditions, heating conditions, and erasing conditions.
Specifically, the ambient temperature of the thermoreversible recording medium after image formation (the ambient temperature is created using a low-humidity constant temperature and humidity chamber ESPEC PDL-4KP, and the surrounding environment is converted into a digital full thermo-hygrometer TRH- Erase printing was carried out under the following printing conditions with the temperature (measured by CA) being 5 ° C., the temperature of the discharged printer tray after printing was set to 30 ° C., and the temperature in the tray case was set to 25 ° C. The discharged medium was left in the tray for 3 minutes, then taken out in a 5 ° C. environment, and erased at 156 mm / sec and 165 ° C. after 5 minutes. The results are shown in Table 5.
The maximum color density at 20 ° C. of the thermoreversible recording medium of Production Example 1 was 1.44, and the maximum color density at 20 ° C. of the thermoreversible recording medium of Production Example 2 was 1.32.
−Printing conditions−
Printing speed: 52mm / sec
Printing energy: 250mW / dot
Thermal head: 300 dpi
Resistance value: 1911Ω
-Heating conditions-
Heating device: Printer tray case temperature 25 ° C
Printer tray temperature 30 ° C
-Erase condition-
Erase speed: 156mm / sec
Heating head: Erase device Erase temperature: 165 ° C

From the results in Table 5, it was found that the color density was increased by heating the medium on which printing was completed in a state where the printer tray case and the printer tray were heated. Further, the unerased density when erasing this was lowered, and sufficient erasability could be secured.

  The image processing method and the image processing apparatus of the present invention remain unerased even when high-speed erasure is performed at an erasing speed of 150 mm / sec or more in a low temperature environment where the ambient temperature of the thermoreversible recording medium after image formation is less than 15 ° C. For example, it is suitable for use in a winter factory.

FIG. 1 is a schematic diagram illustrating an example of an image processing apparatus according to the present invention. FIG. 2 is a schematic diagram showing another example of the image processing apparatus of the present invention. FIG. 3 is a schematic diagram showing still another example of the image processing apparatus of the present invention. FIG. 4 is a graph showing the color-decoloring characteristics of the thermoreversible recording medium. FIG. 5 is a schematic diagram illustrating an example of an RF tag. FIG. 6 is a graph showing the relationship between the environmental temperature and the color density in Example 1. FIG. 7 is a graph showing the relationship between the environmental temperature and the color development rate in Example 1. FIG. 8 is a graph showing the relationship between the environmental temperature and the unerased density in Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Thermoreversible recording medium 38 Heating device 40 Conveyance roller 50 Printer tray 51 RF-ID reader / writer 52 Thermal head 60 Heat processing apparatus 61 Hot air blower 62 Heating container 81 IC chip 82 Antenna 85 RF tag

Claims (9)

An image forming step of forming an image on the thermoreversible recording medium by heating the thermoreversible recording medium whose color tone reversibly changes depending on the temperature;
When the environmental temperature around the thermoreversible recording medium after image formation is less than 15 ° C., the color density A of the image formed on the thermoreversible recording medium and the maximum color density B of the image under the environment of 20 ° C. A color density adjustment step for adjusting the color development rate [(A / B) × 100], which is a ratio of
An image erasing step of erasing an image formed on the thermoreversible recording medium by adjusting the color density and erasing the image formed on the thermoreversible recording medium at an erasing speed of 150 mm / sec or more,
An image processing method, wherein the color development rate is increased as the erasing speed is higher.   The image processing method according to claim 1, wherein in the color density adjustment step, the image surface of the thermoreversible recording medium after image formation is heated to an ambient temperature of 15 ° C. to 20 ° C.   The image processing method according to claim 2, wherein the thermoreversible recording medium after image formation is heated while being conveyed to the printer tray.   The image processing method according to claim 2, wherein the thermoreversible recording medium after image formation is heated at an outlet to the printer tray.   The image processing method according to claim 2, wherein the thermoreversible recording medium after image formation is heated in a printer tray. Thermoreversible recording medium, it has at least a thermally reversible recording layer on the support, it becomes colored state by heating the thermoreversible recording layer in the first specific temperature, the thermoreversible recording layer of emitting color state the image processing method according to any of claims 1 through 3 by Rukoto that Nessu pressurized by the lower than the first specific temperature second specific temperature becomes decolorized state.   The image processing method according to claim 6, wherein the thermoreversible recording layer contains at least an electron donating coloring compound and an electron accepting compound. Image forming means for heating a thermoreversible recording medium whose color tone reversibly changes depending on temperature to form an image on the thermoreversible recording medium;
When the environmental temperature around the thermoreversible recording medium after image formation is less than 15 ° C., the color density A of the image formed on the thermoreversible recording medium and the maximum color density B of the image under the environment of 20 ° C. A color density adjusting means for adjusting the color development rate [(A / B) × 100], which is a ratio of
Image erasing means that heats the thermoreversible recording medium with the color density adjusted and erases the image formed on the thermoreversible recording medium at an erasing speed of 150 mm / sec or more;
An image processing apparatus, wherein the color development rate is increased as the erasing speed increases.   The image processing apparatus according to claim 8, wherein the color density adjusting means is means for heating the image surface of the thermoreversible recording medium after image formation to an ambient temperature of 15 ° C. to 20 ° C.